Management of Common Skin Conditions In General Practice including the “red rash made easy” © Arroll, Fishman & Oakley, Department of General Practice and Primary Health Care University of Auckland, Tamaki Campus Reviewed by Hon A/Prof Amanda Oakley - 2019 http://www.dermnetnz.org Management of Common Skin Conditions In General Practice Contents Page Derm Map 3 Classic location: infants & children 4 Classic location: adults 5 Dermatology terminology 6 Common red rashes 7 Other common skin conditions 12 Common viral infections 14 Common bacterial infections 16 Common fungal infections 17 Arthropods 19 Eczema/dermatitis 20 Benign skin lesions 23 Skin cancers 26 Emergency dermatology 28 Clinical diagnosis of melanoma 31 Principles of diagnosis and treatment 32 Principles of treatment of eczema 33 Treatment sequence for psoriasis 34 Topical corticosteroids 35 Combination topical steroid + antimicrobial 36 Safety with topical corticosteroids 36 Emollients 37 Antipruritics 38 For further information, refer to: http://www.dermnetnz.org And http://www.derm-master.com 2 © Arroll, Fishman & Oakley, Department of General Practice and Primary Health Care, University of Auckland, Tamaki Campus. Management of Common Skin Conditions In General Practice DERM MAP Start Is the patient sick ? Yes Rash could be an infection or a drug eruption? No Insect Bites – Crop of grouped papules with a central blister or scab. Is the patient in pain or the rash Yes Infection: cellulitis / erysipelas, impetigo, boil is swelling, oozing or crusting? / folliculitis, herpes simplex / zoster. Urticaria – Smooth skin surface with weals that evolve in minutes to hours. No Is the rash in a classic location? Yes See our classic location chart . Scabies – Papular rash trunk and limb; burrows in-between fingers and on wrists. No Yes Does the rash have a smooth surface? Eczema / Dermatitis – Localised or generalised rash with several clinical patterns. Is the rash very itchy? Yes Does the rash have a rough or blistered Seborrhoeic Dermatitis – Salmon pink surface? plaques that are thin and indistinct. Not always Psoriasis – Symmetrical plaques that are Yes Does the rash have a diffuse scale? thickened and distinct. Is the rash scaly, but not usually itchy? Tinea Infections – Slowly growing Yes Does the rash have a peripheral scale? asymmetrical plaques; positive mycology. No If diagnosis is obscure, consider swabs, Pityriasis Rosea – Herald patch then smaller Yes scrapings, biopsy, referral; trial of moderate oval plaques along Langer’s lines on upper potency topical steroid and emollients. None of these? trunk. 3 © Arroll, Fishman & Oakley, Department of General Practice and Primary Health Care, University of Auckland, Tamaki Campus. Management of Common Skin Conditions In General Practice Classic Location Chart: Infants and Children 4 © Arroll, Fishman & Oakley, Department of General Practice and Primary Health Care, University of Auckland, Tamaki Campus. Management of Common Skin Conditions In General Practice Classic Location Chart: Adults 5 © Arroll, Fishman & Oakley, Department of General Practice and Primary Health Care, University of Auckland, Tamaki Campus. Management of Common Skin Conditions In General Practice DERMATOLOGY TERMINOLOGY Typical definitions of descriptive terms for skin lesions are given here but are not universally accepted. PRIMARY LESIONS: Macule Small flat area of changed colour, any shape (usually < 10 mm). Patch Flat or flattish area of textural change > 10 mm, any shape. Can be scaly. Papule Solid, elevated lesion < 10 mm in diameter. Plaque Elevated flat-topped lesion usually > 10 mm in diameter; may be composed of confluent papules. Nodule Solid lesion > 10 mm in diameter, often elevated and arising from dermis or subcutaneous tissue. Tumour Benign or malignant growth of tissue. Vesicle Fluid-filled cavity < 10 mm (small blister). The fluid can be clear, serous or haemorrhagic. Umbilicated (depressed centre) if viral origin. Bulla Fluid-filled cavity > 10mm (large blister). May be intraepidermal or subepidermal. Pustule Superficial, white or yellow pus-filled cavity containing neutrophils; may be follicular or non-follicular, infected or non-infected. Abscess Collection of pus in a cavity formed by necrotic tissue. Weal Transient, elevated lesion caused by localised oedema (hive), without surface change, and any shape. Indicates urticaria or urticaria-like condition. Cyst Fluctuant fluid- or semi-fluid filled closed cavity. SECONDARY LESIONS: These result either from the natural evolution of primary lesions (e.g. a vesicle bursts resulting in an erosion) or from the patient’s manipulation of the primary lesion (e.g. scratching resulting in an erosion). Scale Flakes of the horny epithelium, often accompanied by another descriptive term e.g. ‘silvery’, ‘like sandpaper’. Crust (scab) Dried serum, blood, or pus; thin and friable or thick and adherent. Yellow, brown, purple or black in colour. Excoriation A linear, punctate or hollowed-out area, caused by scratching, rubbing, or picking. Lichenification Thickened plaque due to rubbing, resulting in accentuated skin markings and adherent scale. Erosion Loss of part or all of the epidermis; heals without scarring. Shallow moist or crusted lesion. Ulcer Loss of epidermis, at least part of the dermis, and may involve subcutis; heals with scarring. Scar Fibrous tissue or collagen replacing normal skin structures after destruction of some of the dermis. Permanent. The shape of skin lesions may be linear, annular or arcuate or grouped. Distribution may localised or generalised. 6 © Arroll, Fishman & Oakley, Department of General Practice and Primary Health Care, University of Auckland, Tamaki Campus. Management of Common Skin Conditions In General Practice COMMON RED RASHES – localised or widespread change in skin appearance or texture CONDITION LOCATION DESCRIPTION CLUES TO DIAGNOSIS INVESTIGATION MANAGEMENT Acne Face +/- neck, Non-inflammatory Typical site. None. Mild: antiseptic or keratolytic cleanser, chest and back. comedones Mixture of lesions. benzoyl peroxide cream/gel applied to (blackheads and all areas affected. Can add topical whiteheads) and antibiotics but these should not be inflammatory follicular prescribed alone. papules, Moderate: topical retinoid (applied pustules +/- nodules and sparingly to all areas affected areas at cysts. night), oral tetracycline (doxycycline), combined OCP +/- cyproterone Persistent: oral isotretinoin (requires Special Authority application). Severe: start antibiotics and refer to dermatologist. Bacterial Anywhere, Pain and/or fever and/or Pain and/or moist yellow Swab if moist or Topical antiseptic (e.g. hydrogen infection especially face redness. enlarging plaques antibiotics have peroxide cream) short-term if minor (impetigo), (impetigo), follicular failed. only, oral antibiotic in most cases, limbs (boils). pustules (boils). consider IV if patient sick; incise and drain where relevant; refer when relevant. Drug eruption Anywhere, Many different patterns. New drug (1 to 3 Careful history Consider non-drug cause e.g. viral especially trunk. Most often, widespread weeks). (prescribed and infection esp. URTI symptoms & minor morbilliform (measles-like) Clearance on stopping OTC drugs, lesions within mouth. rash +/- fever +/- itch. drug (may take several vitamins, Stop drug. Urticaria next most weeks). herbals). Emollients, topical steroid creams. common morphology. Arrange urgent admission if sick patient (fever, mouth ulcers, blisters, other organ involvement). Eczema Anywhere – Intensely itchy papules or Itch + location + surface Skin swabs for Non-soap cleanser. (see page distribution plaques. dryness / blistering. bacteria and herpes Emollients ++. 20 to 22) depends on Acute eczema is red and Clears rapidly with simplex, if secondary Intermittent topical steroid. specific condition, blistered. appropriate strength infection not clearing See page 33 and 34, 35 to 38 age and cause. Chronic eczema is dry topical steroid. with antibiotics. and thickened. 7 © Arroll, Fishman & Oakley, Department of General Practice and Primary Health Care, University of Auckland, Tamaki Campus. Management of Common Skin Conditions In General Practice COMMON RED RASHES – localised or widespread change in skin appearance or texture CONDITION LOCATION DESCRIPTION CLUES TO DIAGNOSIS INVESTIGATION MANAGEMENT Fungal Anywhere – One or more Slowly enlarging or Skin scrapings for If typical or once diagnosis confirmed, infection esp. toe clefts. asymptomatic to fluctuating plaques. mycology. topical and/or oral antifungal agent. Stop (see page moderately itchy irregular Asymmetrical any topical corticosteroid in use if 17 and 18) plaques, prominent distribution. mycology positive. peripheral scale / maceration. Herpes Lips, genitals, face, Acute eruption of irritable Blisters recur at same Early swab of base of Mild: none, or topical aciclovir. simplex around nails vesicles that crust in a few site from time to time, blister for viral culture Severe: oral aciclovir 200-400 mg (herpetic whitlow) or days. Fever and especially with URTI or and PCR. 5x/day or valaciclovir 500 mg 2x/day x 5 anywhere. lymphadenopathy in when ‘run down’. days.Frequent recurrences: long term primary infection. aciclovir 400 mg bd or valaciclovir 500 mg od. Herpes Dermatomal. Pain precedes erythema Pain; dermatomal Early swab of base of Oral aciclovir 800 mg 5x/day or zoster Unilateral. and vesicles that become distribution of eruption. blister for viral culture valaciclovir 1 g 3x/day for 7days.